1. Field of the Invention
The present invention relates to a controller installed in an electric vehicle including a storage battery in which the higher values of temperature and state of charge are, the larger performance degradation tendency is.
2. Description of the Related Art
A lithium-ion battery is used in an electric vehicle such as an electric car, a fuel cell car, and a hybrid car to supply power to a drive motor and to store power regenerated by the drive motor and power generated by a fuel cell. The lithium-ion battery with a higher temperature and SOC (State Of Charge) value can be more easily degraded. As for a car (electric vehicle) using a storage battery (high-voltage secondary cell) including the lithium-ion battery with such a property, there have been examined various devices and proposals for controlling to keep the storage battery in a good state.
For instance, there is disclosed a battery temperature controller which keeps a temperature of a storage battery within a predetermined range during electrical charge and discharge of the storage battery, so as to control to maintain desired efficiency of the electrical charge and discharge (see JP H05-262144A).
Moreover, there is disclosed a forced-air cooling apparatus of a storage battery for an electric vehicle, which can prevent high temperature degradation of the storage battery with a little power consumption in consideration of outside temperature (see JP 2001-130268A).